Keyboard



FIG. 1 is a top, front perspective view of a keyboard;

FIG. 2 is a top, front perspective view of a second embodiment thereof; and,

FIG. 3 is a top, front perspective view of a third embodiment thereof.

The rear view and the thickness of the keyboard form no part of the claimed design. 

CLAIM The ornamental design for a keyboard, as shown and described. 